This is not complete, but the basics are there. It's a two-engine cluster with rear ejection (how do I do that?). I would like to add a couple of fins in a "v" shape over the engine pods so they're sticking out the side of the rocket but I don't know how to do that.

I thought there used to be baffles in RockSim9, but now I can't find them. The rear engine block is supposed to be a BT-80 baffle. Also, I wanted to add a nosecone at the rear of the rocket instead of the transition. And I want to add the same nosecone at the rear of the outer pods.

In any case, this is a first draft of the design.

What do y'all think?

Attached Files

Double Barrel.rkt (67.3 KB, 109 views)

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Dale Marshall, San Antonio Texas
NAR #90990
Semroc SAM #083

BAR Since 2008
Enjoying model rocketry since 1977.
The Spotted Dragon
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I think it's a winning design, Feyd.

Is this what you had in mind when you said "v" shape over the engine pods?

We have a number of reversed nose cones already in the transitions file, but what you do is just copy the info from a standard NC into a custom transition, make the front diameter the same as the tube, and make the "rear" diameter something like "0.00001" instead of just "0". Match the shape. Copy the shoulder info, too, but remember it's now the "front" shoulder. Clear the "rear" shoulder values.

Attached Files

Double Barrel Mk II.rkt (95.4 KB, 85 views)

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Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
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SAM 0044
AMA 352635

Almost... I was envisioning the fins closer to the body tube. Also, I was thinking of canting the engine pods into the main tube. I thought that would make the look more interesting but I don't think you can do that in RockSim. I may do away with the "V" fins and make the upper and lower fins larger and more "raked". I'll play around with it some more.

Thanks!

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Dale Marshall, San Antonio Texas
NAR #90990
Semroc SAM #083

BAR Since 2008
Enjoying model rocketry since 1977.
The Spotted Dragon
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Here's what I mean about the fins. I've modified the two fins at the bottom of the component list to look more like what I was thinking, and I figured out how to move the fins closer to the main body tube. Plus with those additions, the speed at deployment is now under 2.

Thanks for the assistance!

(Alternate daytime email address: dale.marshall@us.af.mil)

Attached Files

Double Barrel Mk II.rkt (102.0 KB, 92 views)

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Dale Marshall, San Antonio Texas
NAR #90990
Semroc SAM #083

BAR Since 2008
Enjoying model rocketry since 1977.
The Spotted Dragon
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Well, it's about time to start building this beast for the EMRR challenge. I'll likely work on it over the weekend. Any suggestions/tips for painting? It's got a lot of components but I haven't dreamed up a paint scheme for it yet.

Suggestions are welcome!

Another question... I'm considering using composite engines because that would earn me more points in the contest and more power is always good Considering I'm using 24mm tubes for engines mounts, and I don't have a Level 1 certification, what engines are recommended?

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Dale Marshall, San Antonio Texas
NAR #90990
Semroc SAM #083

BAR Since 2008
Enjoying model rocketry since 1977.
The Spotted Dragon
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There are composite D-E-F-G engines which I think would fit in the 24mm tubes, and which do not require any certification. The rules changed last year, so I'm not fully up on what the requirements are for G and beyond.

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Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
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BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635

Cool design. Any concern on the engine exhaust damaging the rear transistion?

You also want to post a pix that those without Rocksim can see it

Thank you.

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you asked for it, you got it!

Some changes - I made the fins all the same size and I moved the two engine pods rearward. I also removed the rear nosecone and small tube section and moved the parachute forward. I had originally made this a rear-ejection model but I've change my mind and made it a standard type ejection, and added a baffle below the parachute. I may make it dual deployment since the top part is so long.

Comments and suggestions are welcome.

Attached Thumbnails

     

Attached Files

Double Barrel Mk II.rkt (108.3 KB, 66 views)

__________________
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Dale Marshall, San Antonio Texas
NAR #90990
Semroc SAM #083

BAR Since 2008
Enjoying model rocketry since 1977.
The Spotted Dragon
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

First try at adding color. I don't want to overwhelm the rocket with lots of different colors, but I don't want it to be boring either. Likely I'm going to have to paint much of it before I put the fins on.

Attached Thumbnails

 

__________________
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Dale Marshall, San Antonio Texas
NAR #90990
Semroc SAM #083

BAR Since 2008
Enjoying model rocketry since 1977.
The Spotted Dragon
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-